omni: add xhdpi symlink for omni_charger

Change-Id: Ia9b6880737c5556bc49ca230c8748b3ab971c08a
diff --git a/charger/images/xhdpi b/charger/images/xhdpi
new file mode 120000
index 0000000..58025eb
--- /dev/null
+++ b/charger/images/xhdpi
@@ -0,0 +1 @@
+480dpi/
\ No newline at end of file